What you need to do before you start

Replacing a faucet is a job you can do yourself with basic tools and about an hour of time. The process is the same whether you are working on a kitchen sink, bathroom sink, or laundry tub: turn off the water, disconnect the old faucet, and install the new one. You do not need a plumber for a straightforward replacement, though you will need to know where your water shutoff valve is and have a wrench, adjustable wrench, and bucket on hand.

Before you buy a new faucet, measure the distance between the holes in your sink or countertop. Most sinks have either one hole (for a single-handle faucet) or three holes (for a two-handle faucet with a separate spout). Some faucets are designed for four-hole or eight-inch spreads. Knowing your hole configuration will save you from buying a faucet that does not fit your sink.

You will also want to check what is underneath your sink. If you have a pedestal sink, a vessel sink, or a wall-mounted faucet, the installation steps change slightly. The instructions that come with your new faucet will show you the exact setup for your model, so read them before you start.

Key Takeaways

  • Turn off the water supply at the shutoff valve under the sink or at the main valve before you disconnect anything.
  • Measure the distance between the holes in your sink to make sure your new faucet will fit.
  • Disconnect the supply lines and mounting nuts with an adjustable wrench, then lift out the old faucet.
  • Install the new faucet by inserting the tailpieces through the sink holes, tightening the mounting nuts from underneath, and reconnecting the supply lines.
  • Turn the water back on slowly and check for leaks at all connection points before you consider the job done.

Turn off the water and clear the space under your sink

Locate the shutoff valve under your sink. It is usually a small oval or round handle on the water line coming from the wall. Turn it clockwise until it stops. If you cannot find a shutoff valve under the sink, or if it does not work, you will need to turn off the main water valve for your house. This is typically in the basement, crawlspace, or outside near the foundation.

Once the water is off, turn on the faucet to release any remaining pressure in the lines. You should see no water come out. Place a bucket under the sink to catch any water that spills when you disconnect the supply lines. Remove any items stored under the sink so you have room to work and can see what you are doing.

Disconnect the old faucet from the supply lines

Look at the two flexible hoses or rigid pipes connected to the bottom of the faucet. These are the hot and cold water supply lines. Use an adjustable wrench to loosen the nut where each line connects to the faucet tailpiece (the pipe sticking down from the faucet). Turn the wrench counterclockwise. Once the nut is loose enough, you can usually unscrew it by hand. Let any remaining water drip into your bucket.

If the supply lines are old and corroded, they may be difficult to turn. Spray them with penetrating oil and wait a few minutes before trying again. Do not force them, or you may crack the fitting. If a line breaks, you will need to replace it along with the faucet.

Remove the mounting nuts and lift out the old faucet

From underneath the sink, locate the mounting nuts that hold the faucet to the sink. These are usually large nuts at the base of each tailpiece. Use your adjustable wrench to loosen them by turning counterclockwise. You may need to hold the faucet steady from above while you turn the nuts below, or ask someone to help you.

Once the nuts are loose, go back to the top of the sink and lift the old faucet straight up and out. It should come free. If it does not budge, check that you have loosened all the nuts and disconnected all the lines. Wipe away any old caulk or putty around the holes with a damp cloth and let the sink dry completely.

Install the new faucet and reconnect the supply lines

Read the instructions that came with your new faucet. Most single-hole faucets have a single tailpiece that goes through the center hole. Two-handle or widespread faucets have multiple tailpieces that go through separate holes. Insert the tailpieces through the correct holes from the top of the sink. From underneath, slide the rubber washers and mounting nuts onto each tailpiece and tighten them with your wrench. Do not overtighten, or you may crack the sink.

Once the faucet is find, connect the supply lines. The hot line (usually marked red or with a red tape) goes to the hot water tailpiece. The cold line (usually marked blue or with a blue tape) goes to the cold water tailpiece. Hand-tighten the nuts first, then use your wrench to snug them another quarter turn. They should be tight enough that they do not leak, but not so tight that you strip the threads.

Turn the water back on and test for leaks

Go back to the shutoff valve and turn it counterclockwise slowly. Let the water run for a few seconds to flush out any debris from the lines. Then turn on the faucet and check the flow from both the hot and cold sides. The water should run smoothly without sputtering.

Look underneath the sink at all the connection points where the supply lines meet the faucet. Wipe the area dry with a cloth, then turn on the faucet again and watch for drips. Check the area again after a few minutes. If you see water dripping, tighten the nut a quarter turn with your wrench and test again. If the leak continues, turn off the water, disconnect the line, and check that the washer inside the nut is seated properly.

Seal around the base of the faucet if needed

If your old faucet had caulk around the base where it meets the sink, your new one probably should too. This prevents water from running down between the faucet and the sink and pooling underneath. Use a caulk gun to explore a thin bead of silicone caulk around the base of the faucet. Smooth it with a wet finger or caulk tool. Let it dry according to the manufacturer's instructions before you use the sink.

If your faucet came with a decorative escutcheon (a ring that covers the hole), install it now according to the instructions. Some escutcheons are glued on, while others screw on from underneath.

Frequently Asked Questions

What if the old faucet is stuck and will not come out?

Spray the mounting nuts with penetrating oil and wait 15 to 20 minutes. Try loosening them again. If they still will not budge, you may need to use a basin wrench, which is a specialized tool that fits in tight spaces under the sink. You can rent one from a hardware store for a few dollars.

Can I reuse the old supply lines with a new faucet?

You can if they are in good condition and the connections match. However, if the lines are more than 10 years old, kinked, or corroded, it is worth replacing them at the same time. New braided stainless steel supply lines cost less than $10 and are more reliable than old rubber hoses.

What if water is leaking from the base of the faucet where it meets the sink?

This usually means the rubber washer under the mounting nut is not seated properly, or the nut is not tight enough. Turn off the water, loosen the nut from underneath, and check that the washer is in place and not cracked. Retighten the nut firmly but do not overtighten. If the washer is damaged, replace it with a new one of the same size.

Do I need to turn off the main water valve or just the valve under the sink?

The shutoff valve under the sink is sufficient for replacing a faucet. You only need the main valve if the under-sink valve does not work or does not exist. Always test the under-sink valve first by turning it off and checking that no water comes out of the faucet.

How long does a new faucet usually last?

A mid-range faucet from a reputable brand typically lasts 15 to 20 years with normal use. Budget faucets may fail sooner, while high-end models can last 25 years or more. The lifespan depends on water quality, how often the faucet is used, and whether the cartridge or valve inside ever needs replacement.